Support is requested for a Keystone Symposia meeting entitled Prophylactic and Therapeutic Antibodies, organized by Margaret Karow and Neil Stahl. The meeting will be held in Keystone, Colorado from February 9- 14, 2014. Until recently, most antibody therapeutics have been indicated for inflammatory diseases and cancer. The success of this approach has led to an expansion to a broader group of diseases such as infection, metabolic diseases, pain, Alzheimer, and bone diseases. This expansion brings a new level of challenge. This meeting will address the development of antibodies for prophylactic- or chronic-use indications that have traditionally been dominated by small molecule therapeutics, with case studies describing the development of antibodies for these market places; how molecule choices, dosing and delivery, and clinical design for efficacy and the minimization of safety risk all impact success. The meeting will also address up and coming approaches such as antibody engineering for pharmacokinetic and pharmacodynamic improvements, the use of vaccines to induce humoral responses in vivo, and use of antibodies to deliver vaccines, as well as look back at what has been learned from chronic therapy of immune diseases. We expect the attendees will be from the fields of translational medicine, antibody generation, pre-clinical pharmacology, and clinical testing, whose work contributes to, and drives, innovation in these fields. It is anticipated that the attendees will come away with an appreciation of these challenges and that the meeting will stimulate research and novel solutions for addressing this group of indications. Opportunities for interdisciplinary interactions will be significantly enhancd by the concurrent meeting on Biology of B Cell Responses, which will share a plenary session on antibody diversity. The topic of the meeting is highly relevant to NIAID's mission to better understand, treat, and ultimately prevent infectious, immunologic, and allergic diseases.